It is known to identify subsurface hydrocarbon reservoirs like hydrocarbon reservoirs by the detection and analyzing of microseeps. Microseeps are defined as leakage of hydrocarbons from subsurface reservoirs to the surface and into the atmosphere. Various different methods are known for detection and analysis of microseeps.
U.S. Pat. No. 4,338,029 to Macourt relates to a method of hydrocarbon exploration wherein air samples are collected while traversing an area by aircraft. Air samples are collected using an air intake, a focusing tube or an aerodyne tube mounted on an aircraft. The air samples are subjected to spectroscopic analysis to determine the extent of halogens and hydrocarbons present in the air samples. The spectrometer is coupled to a navigating system so that the output of the spectrometer can be correlated with the position of the aircraft over the ground. Macourt provides an overall count of the hydrocarbons present in the collected air samples but does not assist in the characterization of the results for the identification of a commercially viable subsurface reservoir.
U.S. Pat. No. 7,542,850 to Humphrey et al. relates to methods for processing geophysical survey data which is collected during aerial exploration of hydrocarbon deposits or ore bodies. More particularly the invention relates to a method for synchronizing data recorded from one or more sensors. The method comprises receiving a first and second geophysical data from a first and second sensor. The geophysical data collected by the two sensors are associated with position and time data to get two sets of merged data. Further, errors can be detected by comparing the merged data.
CA 2,636,180 to Breukelman et al. relates to method for locating and differentiating areas with high shale content from areas of low shale content using gravity gradient measurements. The gravity gradiometer instrument is located in an aircraft which flies in a selected pattern over the terrain to be surveyed and measures one or more components or combinations of components of the gravitational gradient at a plurality of points on said terrain. The measurements are recorded and analyzed to determine and mark deposits large enough to exploit economically.
What is still required in the prior art is to be able to better detect and characterize microseep information for the investigation and differentiation of subsurface formations of interest from the predominant background level of microseep data.